Incident or reflective....old school light meter....

I have a question about using an old school light meter, Gossen Luna Pro with the battery adapter. I shot my first roll of medium format film last week and using my Canon 30d to meter the scene. It works and the shots were a bit overexposed. With the Gossen Luna Pro light meter, I can meter the scene with ambient light or reflective. Let say I want to take a light reading of some tree during the fall foliage and there is a body of water (lake) in between me and the trees. The sun is at my back, 8 o clock. Do I meter this scene with the incident mode? Or do I meter off the reflective light coming from the trees? Would the reflective mode be accurate even when I am no where near my subjects?

Spot metering a mid-tone (partly shaded) area of the water, the fall foliage and other parts of the tree and grass/vegetation then averaging would be better than incident. Your 30d would be metering as a reflective meter by default, and likely in evaluative metering mode (thus, the algorithm of exposure follows the procedure of the Zone System). You could try incident reading from several angles, writing down each reading from each part of the scene, then averaging them all at the end. The problem with incident is that it assumes all parts of the scene are equal in luminance, when they are not, hence the purpose of a spot meter to measure each luminance independently. I am not, at all, a fan or exponent of metering scenes with digital cameras and extrapolating the result to film because it misses valuable learning in understanding how to meter critical parts of the scene to arrive at a correct exposure (although what constitutes "correct" is up to the photographer himself).

If you are able to place yourself in a position that "sees" the same light as your subject, the reading you take will, IMHO, will be the most likely to assist you.

If you take a reflected light meter reading, you will always have to also analyze the acceptance angle of the meter and the reflectivity of the subject before you can reliably use that reading.

In the situation you describe, in order to take a reading off the trees, and just off the trees, you will either need to walk across the water or use a spot meter accessory to limit the angle of view of the meter. Alternatively, you can meter the entire scene and then, using judgement and your experience, estimate how much the reflectivity of the scene differs from the standard 12-18%, and adjust accordingly.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

I have a question about using an old school light meter, Gossen Luna Pro with the battery adapter. I shot my first roll of medium format film last week and using my Canon 30d to meter the scene. It works and the shots were a bit overexposed. With the Gossen Luna Pro light meter, I can meter the scene with ambient light or reflective. Let say I want to take a light reading of some tree during the fall foliage and there is a body of water (lake) in between me and the trees. The sun is at my back, 8 o clock. Do I meter this scene with the incident mode? Or do I meter off the reflective light coming from the trees? Would the reflective mode be accurate even when I am no where near my subjects?

In order to answer that question we need to know what type of film you are using.

Thanks. I don't have the spot meter accessory for my Luna Pro. However, I think this should work by using reflecting metering and metering off the sky and the trees and the body of water in front of me, I can average the value. This should give me somewhat of an accurate reading. No, I don't want to carry my 30D with me while shooting with my medium format body. Obviously, incident reading may not be accurate because the area I am standing is generally under shades.

If you are using reflected light metering, be careful if you meter off of the sky, because it is emitting light, not reflecting it.

And be careful metering off of water, as smooth water reflects images, which can confuse the reading.

An averaged reading is only accurate if the reflectivity of the subject and the light falling on it averages out.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

If you are using reflected light metering, be careful if you meter off of the sky, because it is emitting light, not reflecting it.

And be careful metering off of water, as smooth water reflects images, which can confuse the reading.

An averaged reading is only accurate if the reflectivity of the subject and the light falling on it averages out.

Thanks. What if I meter off the sky in the reflective mode and then the trees to see if there are a huge difference in the exposure values? I would assume the sky would have a higher value. If the difference isn't so great, I would assume averaging both values should give an accurate exposure reading.

Last edited by TooManyShots; 10-17-2012 at 06:09 PM. Click to view previous post history.